PENGAWASAN KUALITI AIR SUNGAI MANUAL
Jabatan Alam Sekitar (JAS) meneruskan program
pengawasan kualiti air sungai pada tahun 2023
bagi menentukan kualiti air sungai dan mengesan
perubahan ke atas kualiti air sungai. Sampel-sampel
air sungai diambil daripada stesen-stesen yang
telah ditetapkan dan diukur kualitinya secara in-situ
serta dihantar ke makmal untuk dianalisa bertujuan
menentukan kriteria dari segi fizik-kimia dan biologi.
Indeks Kualiti Air (IKA) digunakan untuk mengukur
tahap pencemaran dan kesesuaian jenis guna air seperti
yang digariskan di dalam Standard Kualiti Air Negara.
Standard Kualiti Air Negara merupakan standard ambien
untuk melindungi kepelbagaian biologi akuatik serta
ianya juga digunakan sebagai penanda aras untuk
penetapan jenis guna air bagi sungai tertentu.
IKA adalah julat indeks daripada 0 hingga 100 dimana
julat ini dibahagi kepada tiga (3) kategori iaitu
bersih, sederhana tercemar dan tercemar. Indeks ini
berdasarkan kepada enam (6) parameter iaitu oksigen
terlarut (DO), keperluan oksigen biokimia (BOD),
keperluan oksigen kimia (COD), ammoniakal nitrogen
(AN), pepejal terampai (SS) dan pH.
Pada tahun 2023, sebanyak 1,353 stesen pengawasan
kualiti air sungai manual yang merangkumi 672 sungai
telah dipantau di negara ini. Frekuensi persampelan
bagi setiap stesen pengawasan kualiti air sungai
manual dijalankan sebanyak enam (6) kali setahun
dengan jumlah persampelan adalah sebanyak 8,118.
Pelaporan status kualiti air dilaporkan di dalam dua (2)
pendekatan iaitu:-
i. Status kualiti air mengikut sungai; dan
ii. Status kualiti air mengikut stesen
MANUAL RIVER WATER QUALITY MONITORING
The Department of Environment (DOE) continued the
river water quality monitoring programme in 2023,
which is done to determine the status of river water
quality and to detect changes in river water quality.
Water samples were collected from designated stations
for in-situ measurement and sent to the laboratory as
well, for analysis aimed at determining the criteria based
on the sciences of physic-chemical and biological.
The Water Quality Index (WQI) is used to indicate the
level of pollution and the corresponding suitability in
terms of water use according to the National Water
Quality Standards for Malaysia (NWQS). NWQS is an
ambient standard to protect aquatic biodiversity and
it is also used as a benchmark for the setting of uses for
certain rivers.
WQI is an index range from 0 to 100 where the range
is divided into three (3) categories of clean, slightly
polluted and polluted. The index is derived based on
six (6) parameters, which are dissolved oxygen (DO),
biochemical oxygen demand (BOD), chemical oxygen
demand (COD), ammoniacal nitrogen (AN), suspended
solids (SS) and pH.
In 2023, a total of 1,353 manual river water quality
monitoring
stations
covering
672
rivers
were
monitored in this country. The sampling frequency for
each manual river water quality monitoring station is
carried out six (6) times a year with a total sampling of
8,118.
Reporting of water quality status is reported in two (2)
approaches:-
i. River water quality status by river; and
ii. River water quality status by station
KUALITI AIR SUNGAI /
RIVER WATER QUALITY
36
L A P O R A N K U A L I T I A L A M S E K E L I L I N G 2 0 2 3
Bagi pelaporan status kualiti air mengikut sungai, penentuan IKA adalah menggunakan pengiraan secara median dimana median IKA bagi keseluruhan data yang dicerap di setiap stesen untuk mendapatkan IKA sungai tersebut. Pelaporan status kualiti air mengikut sungai adalah menggambarkan status kualiti air bagi keseluruhan sungai berdasarkan jumlah stesen yang dipantau. Manakala bagi pelaporan status kualiti air mengikut stesen, penentuan IKA adalah berdasarkan pengiraan secara median bagi enam (6) IKA di stesen tersebut. Pelaporan status kualiti air mengikut stesen adalah menggambarkan status kualiti air di stesen tersebut sahaja (ANNEX). STATUS KUALITI AIR MENGIKUT SUNGAI Status kualiti air bagi 672 sungai telah dipantau pada tahun 2023. Daripada 672 sungai yang dipantau, sebanyak 486 (72%) sungai dikategorikan sebagai bersih, 161 (24%) sungai dikategorikan sebagai sederhana tercemar dan 25 (4%) dikategorikan sebagai tercemar. Tren bagi kualiti air sungai yang dipantau adalah seperti dalam Rajah 2.1. Bagi pengkelasan IKA, sebanyak 164 (25%) sungai di dalam Kelas I, 363 (54%) sungai di dalam Kelas II, 137 (20%) sungai di Kelas III, dan lapan (8) (1%) sungai di Kelas IV. Indikator utama yang diambil kira untuk menentukan kualiti air sungai berdasarkan parameter BOD, AN dan SS. Punca kemerosotan kualiti air disebabkan oleh pelepasan beban bahan pencemar sama ada daripada punca tetap atau punca tidak tetap. Punca tetap beban pencemaran air adalah punca- punca yang mempunyai takat pelepasan yang boleh dikenalpasti dan tidak berubah dalam masa yang singkat seperti sektor industri, ternakan, sistem rawatan kumbahan dan sebagainya. Manakala punca tidak tetap seperti aktiviti pertanian, kerja tanah, perlombongan dan kumbahan bukan najis (air cucian dapur dan bilik air selain kumbahan) tidak mempunyai takat pelepasan yang tetap dan For water quality status reporting by river, the WQI determination is based on the median calculation where the median WQI for the entire data observed at each station to obtain the river WQI. The reporting of water quality status by river is a reflection of the quality status of the entire river based on the number of stations monitored. While for water quality status reporting by station, the WQI determination is based on the median calculation of six (6) WQI at the station. The reporting of water quality status by station is a reflection of the quality status at the station only (ANNEX). WATER QUALITY STATUS BY RIVER The water quality status of a total of 672 rivers were monitored in 2023. Out of the 672 rivers monitored, the water quality of 486 (72%) rivers were indicated as clean, 161 (24%) rivers were indicated as slightly polluted and 25 (4%) rivers were indicated as polluted. The trend of the monitored rivers water quality as shown in Figure 2.1. For WQI classification, as many as 164 (25%) rivers are in Class I, 363 (54%) rivers are in Class II, 137 (20%) rivers are in Class III, and eight (8) (1%) rivers are in Class IV . The main indicators were considered to determine the quality of river water based on the parameters of BOD, AN and SS. The cause of the deterioration of water quality is due to the discharge of the pollution load either from a point source or from a nonpoint source. Point sources can be described as pollution sources that have specific identifiable discharge points which are unchanged over time. Sectors such as industry, livestock and sewage treatment systems fall under this category. Meanwhile the nonpoint sources such agricultural activities, earthworks, mining, and sullage (domestic wastewater other than sewage such as kitchen and bathroom wastewater) do not have specific 37 E N V I R O N M E N T A L Q U A L I T Y R E P O R T 2 0 2 3 RIVER WATER QUALITY
Rajah 2.1: Tren Kualiti Air Sungai, 2019-2023 Figure 2.1: River Water Quality Trend, 2019-2023 Tahun / Year Peratus Bilangan Sungai / Percentage Number of River 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 2019 672 61% 30% 9% 66% 29% 5% 73% 24% 74% 22% 4% 72% 24% 4% 2020 672 2022 672 2023 672 2021 670 3% Bersih / Clean Sederhana Tercemar / Slightly Polluted Tercemar / Polluted Jumlah Sungai / Total Number of River 0% sering berubah-ubah yang menyukarkan anggaran pelepasan beban pencemaran dibuat. Kajian berkaitan beban pencemaran di bawah kategori ini bagi Malaysia tidak banyak dibuat dan tersedia untuk rujukan buat masa ini. BOD adalah jumlah oksigen yang diperlukan oleh bakteria atau mikroorganisma yang lain untuk menguraikan bahan organik. Kepekatan BOD yang tinggi kerap kali dikaitkan dengan pelepasan efluen yang berterusan daripada industri. AN adalah dikaitkan dengan aktiviti penternakan haiwan berkaki dan kumbahan domestik. Manakala SS dikaitkan dengan kerja-kerja tanah yang tidak teratur dan aktiviti pembukaan tanah yang tidak terkawal. identifiable discharge points and the locations are varied over time. This makes it difficult to estimate the amount of released pollution loads. BOD is the amount of oxygen required by bacteria or other microorganisms to decompose organic matter. High BOD concentrations are often associated with continuous discharge of effluents from industries. AN is associated with livestock farming activities and domestic sewage, while SS is caused by improper earthworks and uncontrolled land clearing activities. 38 L A P O R A N K U A L I T I A L A M S E K E L I L I N G 2 0 2 3 KUALITI AIR SUNGAI
Jadual 2.2 menunjukkan kualiti air sungai yang
dikategorikan sebagai tercemar berdasarkan sub-
indeks BOD, AN dan SS pada tahun 2023. Daripada
25 sungai yang dikategorikan sebagai tercemar,
sebanyak 17 sungai adalah berada di Kelas III manakala
lapan (8) sungai adalah di Kelas IV.
Berdasarkan sub-indeks BOD, hanya satu (1) sungai
berada di Kelas I, tiga (3) sungai di Kelas II, satu (1)
sungai di Kelas III, tujuh (7) sungai di Kelas IV dan
selebihnya 13 sungai adalah di Kelas V.
Dari segi sub-indeks AN pula, hanya satu (1) sungai
berada di Kelas I, dua (2) sungai di Kelas II, tiga (3) sungai
di Kelas III, dua (2) sungai di Kelas IV dan selebihnya
17 sungai adalah di Kelas V.
Dari segi sub-indeks SS, 18 sungai yang berada di
Kelas I, lima (5) sungai di Kelas II dan dua (2) sungai
adalah di Kelas III.
Table 2.2 shows the quality of river water categorised
as polluted based on the BOD, AN and SS sub-indexes
in 2023. Out of the 25 rivers categorised as polluted,
17 rivers were in Class III while eight (8) rivers were in
Class IV.
Based on the BOD sub-index, only one (1) river was in
Class I, three (3) rivers in Class II, one (1) river in Class III,
seven (7) rivers in Class IV and the remaining 13 rivers
were in Class V.
In terms of sub-index AN, only one (1) river was in
Class I, two (2) rivers in Class II, three (3) rivers in
Class III, two (2) rivers in Class IV and the remaining 17
rivers were in Class V.
In terms of SS sub-index, 18 rivers were in Class I, five (5)
rivers in Class II and two (2) rivers in Class III.
Jadual 2.1: Status Kualiti Air Sungai Mengikut Stesen, 2022
Table 2.1: Water Quality Status by Stations, 2022
NEGERI / STATE
LEMBANGAN / BASIN
SUNGAI / RIVER
NILAI IKA / WQI VALUE
KATEGORI IKA
(2023) /
WQI CATEGORY
(2023)
2019
2020
2021
2022
2023
Perlis
Sg. Perlis
Sg. Arau
82
83
89
88
89
B/C
Sg. Empangan Timah Tasoh
87
93
95
96
95
B/C
Sg. Jarum
83
88
91
89
88
B/C
Sg. Jernih
86
91
93
95
94
B/C
Sg. Kok Mak
86
88
87
88
86
B/C
Sg. Korok
71
75
76
74
79
ST/SP
Sg. Ngulang
82
90
92
93
88
B/C
Sg. Pelarit
91
94
96
96
96
B/C
Sg. Perlis
72
76
77
78
81
B/C
Sg. Serai
76
82
86
90
86
B/C
Sg. Terusan Mada
85
88
91
91
92
B/C
Sg. Wang Kelian
94
95
97
97
97
B/C
Kedah
Sg. Kedah
Sg. Ahning
88
92
96
95
94
B/C
Sg. Changlun
77
87
88
87
86
B/C
Sg. Janing
91
93
97
97
97
B/C
Sg. Kedah
64
70
77
76
73
ST/SP
Sg. Napoh
80
82
89
90
88
B/C
Sg. Padang Terap
87
86
93
91
92
B/C
Sg. Pedu
90
91
95
94
95
B/C
Sg. Pendang
77
81
82
85
85
B/C
Sg. Sintok
81
92
96
95
92
B/C
Sg. Tekai
80
88
94
93
91
B/C
Sg. Temin
77
84
89
89
87
B/C
Sg. Terusan Lengkuas
89
86
92
92
93
B/C
Sg. Terusan Mada Selatan
88
89
92
90
91
B/C
Sg. Terusan Tengah
89
88
93
93
94
B/C
Sg. Kisap
Sg. Kisap
90
95
97
97
96
B/C
Sg. Kuah
Sg. Kuah
74
81
79
81
69
ST/SP
Jadual 2.1: Status Kualiti Air Sungai Mengikut Sungai, 2023
Table 2.1: Water Quality Status by River, 2023
39
E N V I R O N M E N T A L Q U A L I T Y R E P O R T 2 0 2 3
RIVER WATER QUALITY